BRCA2, located on chromosome 13q12-q13, consists of over 70 kb of genomic DNA. The coding sequence produces a protein of 3,418 amino acids. Although most of the exons are small, exons 10 and 11 represent approximately 60% of the entire coding region. BRCA2 is thought to be a tumor suppressor gene associated with breast and ovarian cancer. Thus mutantions which form an altered tumor suppressor or altered concentrations of tumor suppressor may be indicative of a higher succeptibility to certain cancers.
The nucleotide sequence for at least one BRCA2 gene is known and is reported in GENBANK accession Number U43746. The BRCA2 gene sequence is available on the Breast Cancer Information Core.
Germline mutations of BRCA2 are predicted to account for approximately 35% of families with multiple case, early onset female breast cancer, and they are also associated with an increased risk of male breast cancer, ovarian cancer, prostrate cancer and pancreatic cancer.
The location of one or more mutations of the BRCA2 gene provides a promising approach to reducing the high incidence and mortality associated with breast and ovarian cancer through the early detection of women at high risk. These women, once identified, can be targeted for more aggressive prevention programs. Screening is carried out by a variety of methods which include karyotyping, probe binding and DNA sequencing. In such cases where one or only a few known mutations are responsible for the disease, such as testing family members, methods for detecting the mutations are targeted to the site within the gene at which they are known to occur.
Many mutations and normal polymorphisms have already been reported in the BRCA2 gene. A world wide web site has been built to facilitate the detection and characterization of alterations in breast cancer susceptibility genes. Such mutations in BRCA2 can be accessed through the Breast Cancer Information Core at:
HTTP://www.nchgr.nih.gov/dir/lab.sub.-- transfer/bic. PA0 BRCA2-11F 5'TGG TAC TTT AAT TTT GTC ACT T3' SEQ ID NO:1 PA0 BRCA2-11R 5'TGC AGG CAT GAC AGA GAA T3' SEQ ID NO:2 PA0 5'TGA AGA ACC AAC TTT GT3' SEQ ID NO:3 PA0 5'TGA AGA ACG AAC TTT GT3' SEQ ID NO:4 PA0 5'TGA AGA ACC AAC TTT GT3', SEQ ID NO:3, hybridizes preferentially to the wildtype sequence and is useful as a control sequence. 5'TGA AGA ACG AAC TTT GT3', SEQ ID NO:4, is designed to hybridize preferentially to the mutant sequence. PA0 BRCA2-11F 5'CTC AGA TGT TAT TTT CCA AGC3' SEQ ID NO:5 PA0 BRCA2-11R 5'CTG TTA AAT AAC CAG AAG CAC3' SEQ ID NO:6 PA0 5'GCA AGC AAT TTG AAG GT3' SEQ ID NO:7 PA0 5'GCA AGC AAT GAA GGT AC3' SEQ ID NO:8 PA0 BRCA2-11F 5'GCA AAG ACC CTA AAG TAC AG3', SEQ ID NO:9 PA0 BRCA2-11R 5'CAT CAA ATA TTC CTT CTC TAA G3', SEQ ID NO:10 PA0 5'ACT TGT TAC ACA AAT CA3', SEQ ID NO:11 PA0 5'ACT TGT TAG ACA AAT CA3', SEQ ID NO:12 PA0 BRCA2-11F 5'GAA AAT TCA GCC TTA GC3' SEQ ID NO:13 PA0 BRCA2-11R 5'ATC AGA ATG GTA GGA AT3' SEQ ID NO:14 PA0 5'ATT ATT TGT ATG AAA AT3' SEQ ID NO:15 PA0 5'ATT ATT TGA AAA TAA TT3' SEQ ID NO:16 PA0 BRCA2-11F 5'TAC AGC AAG TGG AAA GC3' SEQ ID NO:17 PA0 BRCA2-11R 5'AAG TTT CAG TTT TAC CAA T3' SEQ ID NO:18 PA0 5'GAA CTG AGC ATA GTC TT3' SEQ ID NO:19 PA0 5'GAA CTG AAT AGT CTT CA3' SEQ ID NO:20 PA0 BRCA2-11F 5'ACT TTT TCT GAT GTT CCT GTG3' SEQ ID NO:21 PA0 BRCA2-11R 5'TAA AAA TAG TGA TTG GCA ACA3' SEQ ID NO:22 PA0 5'CAG AAG CAG TAG AAA TT3' SEQ ID NO:23 PA0 5'CAG AAG CAG GTA GAA AT3' SEQ ID NO:24
While mutations occur throughtout the BRCA2 gene, there is a need for a high sample number (throughput), sensitivity, accuracy and cost effectiveness. Identification of mutations of the BRCA2 gene would allow more widespread diagnostic screening for hereditary breast and ovarian cancer than is currently possible and permit identification of functional areas deduced from the mutational spectrum observed.